Liquefied petroleum gas vaporizer having a surge chamber



5. P- JONES A rJil .6, 1965 LI'QUEFIED PETROLEUM GAS VAPORIZER HAVING A SURGE CHAMBER Filed (Aug. 15, 1962 4 Sheets-Sheet '1 INVENTOR Sam I? Jones FIGJ ATTORNEYS April 6, 1965 S. P. JONES Filed Aug. 13, 1962 J L s FIG. 2

4 Sheets-Sheet 2 ATTORNEYS p 6. 1965 5.. P1 JONES 3,176,109"

LIQUEFIED P'ETROI JEUMK GAS? VWP'ORTZ ERE' H'IWING? A" SURGE CHAMBER ar I 2 4 Sheets-Sheet. s

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re 47 26 44 17% INVENTOR Sam F2 Jones Fuse 1 BY 9/ v ATTORNEYS S. P. JO NZEJS April 6, 1965 EI gIJ-EEIEE PETROLEUM (ms VEEORIEEE Haw rm A SURGE CHAMBER Filed; Aug, 15, 196-2 4 She a ts-She ed: 4

INVENTOR Sum P. Jones ATTORNEYS him A United States Patent 3,176,709 LIQUEFED PETROLEUM GAS VAPGRKZER HAVING A SURGE CHAMBER Sam P. Jones, Dallas, Tern, assignor to .F. & S.

Carburetor (Iompany, Dallas, Tern, a corporation of Texas Filed Aug. 13, 1962., Ser. No. 216,684 6 Claims. (Cl. 137-640) This invention relates to new and useful improvements in Vaporizers for liquefied petroleum gas for use in the carburetors of internal combustion engines.

One object of the invention is to provide an improved vaporizer for liquefied petroleum gas wherein the pressure of the gas is reduced by expansion, wherein the gas is converted from a liquid to a vapor by contact with a heated surface as well as additional expansion, and wherein the vaporized gas i reduced to a pressure slightly below atmospheric for withdrawal into a carburetor of an internal combustion engine.

A particular object of the invention is to provide an improved liquefied petroleum gas vaporizer wherein the liquid fuel is withdrawn from contact with hot vaporizing surfaces, as the demand for fuel diminishes and the pressure within the vaporizer increases, into a chamber which is isolated from vaporizing surfaces and heated liquid and which is of substantially the same temperature as the unheated liquid fuel so as to prevent the wastage of fuel and creation of a fire hazard due to excessive pressure.

An important object of the invention is to provide an improved vaporizer having a surge chamber for receiving liquid fuel from a vaporizing chamber to prevent the pressure in the vaporizer from exceeding a predeterminedlimit, the surge chamber being disposed between the vaporizing chamber and a chamber containing unheated liquid fuel so as to be cold for maintaining the fuel therein liquefied and at a relatively low pressure.

Another object of the invention is to provide an improved vaporizer of the character described, having a substantially annular sunge channel disposed within a substantially annular vaporizing channel which is surrounded by a substantially annular hot channel, the surge channel surrounding a chamber containing unheated liquid fuel and communicating with the lowest point of the vaporizing channel for receiving liquid fuel therefrom to prevent vaporization thereof and the creation of excessive pressure, the liquid in said vaporization channel tending to cling to the outer wall thereof so as to be spaced from the outer wall of said surge channel whereby the outer surface of the latter wall is moisture-free and frost does not form thereon and reduce the eificiency of the vaporizer.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown, and wherein:

FIG. 1 is a front \elevational view, with the front cover plate and diaphragm removed, of a liquefied petroleum gas vaporizer constructed in accordance with the invention,

FIG. 2 i a transverse, sectional view, taken on the line 2-2 of FIG. 1, showing the communication between the inner or surge chamber and the intermediate or expausion chamber,

FIG. 3 is a transverse, sectional view, taken on the line 3-3 of FIG. 1, showing the vent for the high pressure diaphragm, V FIG. 4 is a fragmentary elevational view showing the outlet for the vaporized gas,

3,1171% Patented Apr. 6, 1965 FIG. 5 is a rear elevational view, with the rear cover plate and diaphragm removed, taken on the line 5-5 of FIG. 2,

FIG, 6 is a transverse, sectional view, taken on the line 6-6 of FIG. 1, showing the hot Water inlet,

FIG. 7 is a view, similar to FIG. 6 and taken on the line '7-7 of PEG. 1, showing the hot water outlet,

FIG. 8 is a transverse, sectional view, taken on the line E-8 of FIG. 1, showing the liquefied gas inlet, and

FIG. 9 is a transverse, sectional view, taken on the line 9-9 of FIG. 5, showing the valve for controlling the flow of vaporized gas from the vaporizing chamber to the gas outlet.

In the drawings, the numeral 14) designates the cylindrical casing or housing of a vaporizer for liquefied petroleum gas, such as butane and/or propane. The housing has an annular, side wall 11, of narrow width, and a pair of circular end walls or front and rear cover plates 12 and 13, of the same diameter, fastened to the side wall by suitable screws 14. Ears or lugs 15 for mounting the vaporizer housing may project radially from the rear plate 13. The housing has a circular partition 16 extending diametrically thereof and dividing its interior into circular high and low pressure chambers 17 and T8, the high pressure chamber 17 being of smaller diameter than the low pressure chamber 13 and having its inner end wall 19 formed by offsetting the axial or central portion of the partition toward the front plate 12 (FIG. 2). A plurality of substantially annular, concentric, spaced walls 2t), 2t and 22 surround the high pressure chamber 17 to provide a plurality of substantially annular, concentric chambers or channels 23, 2d and 25. The outer channel 23 is formed between the walls lit and 20, the intermediate or vaporizing channel 24 between the walls 23 and 21, land the inner or surge channel 25 between the walls 21 and 22, said wall 22 forming the side wall of the chamber 17. Preferably, the screws 14 secure the front plate 12 to the Walls 21 and 23 as well as to the outer side wall ill.

As shown in FIGS. 2, 6 and 7, an inlet 26 and an outlet 2'7 communicate with the outer channel 23 for conducting hot water or other heat exchange fluid therethrough and said channel may have a drain plug :23 at its lower portion. The vaporizing and surge channels 24 and 25 communicate with each other by means of a radial port 29 extending from said surge channel 25 through the outer side wall 11 of the housing and an axiallyextending aperture 30 between said vaporizing chamber 24 and the port 29, the outer end of the port being closed by a plug 31 (FIG. 2). It is noted that the aperture 30 opens into the lowest point of the vaporizing channel. One end of the channel 24 is enlarged to provide a recess 32 which opens into the high pressure chamber 17 (FIG. 1) and which has an angular inlet port33 communicating therewith for admitting liquefied gas thereto (FIG. 8). The inlet port 33 has its outer leg directed radially through the housing side wall 11 for communicating with a supply pipe 34 and its inner leg directed axially to receive a flanged valve seat 35. A suitable. fitting 36 overlies the valve seat 35 and is secured to the bottom of the recess 32 for confining said seat against displacement. The fitting as pivotally supports an arm or lever 37 having a valve disk or member 38 at its outer end for overlying the valve seat and a boss 39 at its inner end, which inner end is of greater length than said outer end and extends radially into the chamber 17, for confining a helical spring db between said inner end and the inner end wall 19 of said chamber whereby the value disk is urged into engagement with said valve seat.

The inner end of the arm 37 extends at least to the center of the high pressure chamber 17 for coacting with a pressure-responsive member or diaphragm 41 having a circular reinforcing plate or disk 42 of smaller diameter than and in axial alinement with said chamber. As shown by the numeral 43 in FIG. 2, the central portion of the front cover plate 12 has a circular recess of greater diameter than the disk 42 to permit outward flexing of the diaphragm 41. The latter is of substantially the same diameter as the front cover plate and is adapted to have its major portion interposed and clamped between said plate and the walls 11, 2t 21 and 22 by the screws 14- in overlaying relation to the channels 23, 24 and 25 as well as the recess 32. if desired, an annular gasket may be disposed between the cover plate and the clamped major portion of the diaphragm 41. An axial, hollow boss or protuberance 45 projects from the cover plate 12 and has its interior communicating with the recess 45 for accommodating a helical spring 46 which bears against the disk 42 for urging the diaphragm inwardly toward the inner end of the arm 37. The spring 46 is confined and its compression is controlled by a plug 47 screwthreaded in the outer end of the boss 45 and having an elongated, frusto-conical follower 48 engaged within the outer end portion of said spring.

An axial bore 49, of small diameter, is provided in the follower 48 of the plug 47 for receiving the guide rod i) of a bearing element 51 which has a stem or shank portion 52 projecting through the centers of the diaphragm ll and disk 42. The element 51 is in the form of a disk or button overlying the inner surface of the diaphragm for engagemerit with the arm 37, and a helical spring 53 is confined on the stem 52 between said diaphragm and the plug follower by suitable followers 54 for holding the said element engaged with said diaphragm. Due to the diaphragm and its disk being urged inwardly by the spring 46, normally, the element bears against the inner end of the arm so as to unseat the valve member 38 (FIG. 8) for admitting liquefied gas to the recess 32 as well as the high pressure chamber 17' and vaporizing chamber 24. Whenever the pressure of this gas becomes sufficient to overcome the force of the spring 46, the diaphragm 4i flexes outwardly to move the element 51 away from the arm 37 and permit clockwise pivoting of said arm by the spring 40 to engage the valve member with the valve seat 35 and shut oif the admission of liquified gas. In addition to providing a bearing surface for engagement with the arm, the element seals the opening of the diaphragm through which its stem extends and its spring-pressed mounting permits relative outward movement of said diaphragm.

The liquefied gas expands and vaporizes in the channel 24 and flows therefrom into the low pressure chamber 18 through an axially-extending opening 55 in the partition to at the closed end of said channel opposite yet adjacent the recess 32 (FIG. 9). A' suitable valve 56 is mounted in the opening 55 and is urged into engagement with a complementary seat 57, which faces the channel, by a helical spring 53 confined between the valve and a suitable follower 5% wedged or otherwise secured in said channel. The valve seat 57.is carried by a fitting 6i having a guide spider 61 for confining the valve as against displacement, and is suitably fastened to the partition on its chamber side (FIG. 5). An arm or lever 62 is pivotab ly mounted on the fitting 66 in overlying relation to the valve and extends radially inward thereof for u seating said valve to admit gas from the channel 24 to the chamber 18. The outer end portion of the arm as carries buttons or bearing elements 63 and in spaced longitudinally of said arm and projecting outwardly toward the rear cover plate 13. As shown most clearly in FIG. 9, the endmost button 63 projects to a greater extent than the button 64 and this may be due to the angularity of the arm. A pressure-responsive member or diaphragm 65 has its periphery clamped between the outer side wall lit and the rear cover plate by the screws 14 so as to extend diametrically of the low pressure chamber and has an axial, circular, reinforcing plate or disk 66, of smaller diameter, on its inner surface for engagement by the buttons of the arm 62. The diaphragm 65, which may be confined between annular gaskets 67, has its outer surface exposed to atmospheric pressure through a suitable inlet 68 in the plate 13 (FIG. 2) and its inner surface exposed to the chamber 18 and to a gas outlet 69 in the wall ll (FIG. 9). Preferably, a fitting 79 is rotatably mounted on the outlet 69 for connection with the carburetor (not shown) of an internal combustion engine.

The valve 56 is of the type having a longitudinal here with a spring-pressed valve core 71 mounted therein and projecting therefrom for engagement by the arm 62. Inward pivoting of the arm initially depresses and unseats the valve core 71 and continued inward pivoting depresses and unseats the valve to admit gas from the channel 24 to the chamber 18. The pressure of this gas is slightly below atmospheric and is withdrawn from the chamber by the suction of the carburetion system of the engine. Since its outer surface is exposed to atmospheric pressure, the diaphragm is flexed inwardly to engage its disk 66 with the endrnost button 63 and thereby unseat the valve core. Continued inward flexing of the diaphragm engages its disk with the button 64 to unseat the valve 5d. Whenever the gas within the chamber approaches atmospheric pressure, such as when no gas is being withdrawn from said chamber, the force of the spring 58'is sufficient to seat the valve and pivot the arm 62 outwardly and thereby cause outward flexing of the diaphragm and permit seating of the valve core 71. As shown most clearly in FIG. 3, the chamber 13 communicates with the recess 43 and the interior of the boss 45 through an angular aperture 72 in the inner surface of the front cover plate 12 and a port 73 extending axially through the wall 22 to permit the venting of any pressure fluid which might leak into said recess and boss through the diaphragm 41 around the stem 52 of the element 51.

In operation, liquefied gas enters the vaporizing channel 24- as well as the high pressure chamber 17 through the inlet port 33, valve seat 35 and recess 32 (FIG. 8) and expands due to the comparatively large volumes of said channel and chamber and vaporizes due to contact with the warm wall 20 which is heated by the hot water conducted through the channel 23. From the channel, the gas flows through the opening 55 into the low pressure chamber'l8 (FIG. 9) wherein it further expands so as to further reduce its pressure. As has been explained, the liquefied gas or liquefied fuel continues to enter the channel 24 until the ressure in the chamber 17 becomes suificient to overcome the force of the spring as so as to flex the diaphragm 41 outwardly and permit the spring 40 to pivot the arm 37 clockwise for seating the valve member 38. Also, the vaporized gas or gaseous fuel continues to flow from the channel 24 into the chamber 17 until the pressure in said chamber becomes sufiicient to flex the diaphragm 65 outwardly and permit seating of the valve 56 to reduce the rate of flow in accordance with the withdrawal of gas from said chamber. If withdrawal ceases, the pressure increases and flexes the diaphragm additionally to permit seating of the valve core 71.

When the withdrawal of gaseous fuel is halted or diminished, the liquid fuel remaining in the channel 24 continues to vaporize and the pressure thereof commences to increase. If the period of reduced fuel consumption is of prolonged duration or the decrease in consumption is rapid and of appreciable magnitude, the pressure within the channel increases rapidly due to the vaporization of the liquid fuel therein and may quickly exceed a predetermined safety limit. Instead of venting this excessive pressure to atmosphere, such as through the engine and its exhaust manifold (not shown) which is wasteful and may enrich the fuel mixture sufficiently to cause stalling of said engine, the liquid fuel may flowinto the surge channel 25 through the aperture 30 and port 29. As a result, the liquid fuel is withdrawn from contact with the warm wall 20 of the heated channel 23 as soon as the pres sure begins to build up in the vaporizing channel 24 and said pressure tends to force said liquid fuel into the surge channel 25. Since the latter channel is spaced from the 55 heated channel 23 and is adjacent the liquid fuel in the chamber 17, due to the common wall 22 therebetween, it is cold and no vaporization occurs therein whereby there is no wastage of fuel nor supplying of overly rich mixture to the engine.

As soon as the withdrawal of gaseous fuel from the chamber 18 is resumed or increased, the :liquid fuel in the channel 25 returns to the channel 24 and the operation continues in the manner described. It is preferable for the walls 20 and 21 to undulate so as to increase the length of the channels 23 and 24 as well as the area of said wall 20 for contact by the liquid fuel. Attention is directed to the fact that any gaseous fuel which enters the surge channel 25 immediately condenses and liquefies due to the coldness of said channel resulting from its proximity to the unheated liquid fuel in the high pressure chamber 17 and its isolation from the warm liquid in the vaporizing channel 24- which tends to cling to the outer wall 21 of said channel 24 and which is heated and vaporized by such contact. Even when propane is used as the fuel for the engine, the temperature of the surge channel may be as low as 35 below zero Without frost forming on the exterior of the wall 21 because it is exposed only to gas that is free of moisture.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as Well as in the details of the illustrated construction may be made, Within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. A vaporizer for liquefied petroleum gas including a casing having a high pressure chamber for receiving liquefied petroleum gas from a supply source, means for expanding the gas from the supply source into the high pressure chamber to reduce the temperature of said gas, a vaporizing chamber communicating with the high pressure chamber and for receiving the expanded gas therefrom, a hot chamber surrounding the vaporizing chamber in heat exchange relations-hip and having an inlet and an outlet for conducting a heat exchange fluid therethrough whereby the gas vaporizes in said vaporizing chamber, a low pressure chamber communicating with said vaporizing chamber in spaced relation to its communication with said high pressure chamber for receiving and discharging warm vaporized gas, and a surge chamber between said high pressure and vaporizing chambers and having restricted communication with the lower portion of said vaporizing chamber for receiving therefrom liquid under pressure createdby continued vaporization within said vaporizing chamber after the gas demand is reduced so as to retard vaporization and the discharge of Warm vaporized gas until the demand therefor is increased, the surge chamber being in heat exchange relationship to said high pressure chamber so as to be cold due to its exposure to the low temperature of the liquefied gas in said high pressure chamber.

2. A vaporizer as set forth in claim 1 wherein the surge chamber substantially surrounds the high pressure chamber and is spaced from the hot chamber.

3. A vaporizer as set forth in claim 1 wherein the vaporizing, hot and surge chambers are in the form of substantially annular channels, the surge channel substantially surrounding the high pressure chamber and being substantially surrounded by the vaporizing channel so as to be spaced from the hot channel.

4. A vaporizer as set forth in claim 1 wherein the surge chamber has a passage communicating with the low point of the vaporizing chamber for conducting liquid to and from said chambers and providing the restricted communication therebetween.

5. A vaporizer as set forth in claim 1 wherein the vaporizing chamber is in the form of a substantially annular channel having one of its ends communicating with the high pressure chamber, the vaporizing channel being disposed in surrounding relation to said high pressure cham her with its major portion spaced therefrom by the surge chamber.

6. A vaporizer as set forth in claim 1 wherein the vaporizing, hot and surge chambers are in the form of substantially annular channels, the surge channel substantially surrounding the high pressure chamber and being substantially surrounded by the vaporizing channel so as to be spaced from the hot channel, said surge channel having an inner wall in common with the wall of said high pressure chamber and an outer wall in common with the inner wall of said vaporizing channel, the latter channel having an outer wall in common with the inner Wall of said hot channel.

References (Iited by the Examiner UNITED STATES PATENTS 2,248,222 7/41 Ensign 137340 2,731,801 1/56 Reed 137-340 2,858,845 11/58 Ensign 137340 M. CARY NELSON, Primary Examiner. 

1. A VAPORIZER FOR LIQUEFIED PETROLEUM GAS INCLUDING A CASING HAVING A HIGH PRESSURE CHAMBER FOR RECIEVING LIQUEFIED PETORLEUM GAS FROM A SUPLY SOURCE, MEAND FOR EXPANDING THE GAS FROM THE SUPPLY SOURCE INTO THE HIGH PRESSURE CHAMBER TO REDUCE THE TEMPERATURE OF SAID GAS, A VAPORIZING CHAMBER COMMUNICATING WITH THE HIGH PRESSURE CHAMBER AND FOR RECEIVING THE EXPANDD GAS THEREFROM, A HOT CHAMBER SURROUNDING THE VAPORIZING CHAMBER IN HEAT EXCHANGE RELATIONSHIP AND HAVING AN INLET AND AN OUTLET FOR CONDUCTING A HEAT EXCHANGE THERETHROUGH WHEREBY THE GAS VAPORIZES IN SAID VAPORIZING CHAMBER, A LOW PRESSURE CHAMBER COMMUNICATING WITH SAID VAPORIZING CAMBER IN SPACED RELATION TO ITS COMMUNICATION WITH SAID HIGH PRESSURE CHAMBER FOR RECEIVING AND DISCHARGING WARM VAPORIZED GAS, AND A SURGE CHAMBER BETWEEN SAID HIGH PRESSURE AND VAPORIZING CHAMBERS AND HAVING RESTRICTED COMMUNICATIONS WITH THE LOWER PORTIONS OF SAID VAPORIZING CHAMBER FOR RECEIVING THEREFROM LIQUID UNDER PRESSURE CREATED BY CONTINUED BAPORIZATION WITHIN SAID VAPORIZING CHAMBER AFTER THE GAS DEMAND IS REDUCED SO AS TO RETARD VAPORIZATION AND THE DISCHARGE OF WARM VAPORIZED UNTIL THE DEMAND THEREFOR IS INCREASED, THE SURGE CHAMBER BEING IN HEAT EXCHANGE RELATIONSHIP TO SAID HIGH PRESSURE CHAMBER SO AS TO BE COLD DUE TO ITS EXPOSURE TO THE LOW TEMPERATURE OF THE LIQUEFIED GAS IN SAID HIGH PRESSURE CHAMBER. 